Lenticular lens sheet, rear projection type screen, and method of manufacturing lenticular lens sheet

Abstract

A lenticular lens sheet that is bonded to a front faceplate and used in a rear projection type screen is disclosed. The lenticular lens sheet has a plurality of lenticular lenses arranged on one surface of a light-transmitting substrate, and projecting non-convergence parts arranged on the other surface of the light-transmitting substrate in positions different to positions of convergence of light from the lenticular lenses. An external light absorbing layer that absorbs external light is provided on a summit portion of each of the projecting non-convergence parts. Also, the lenticular lens sheet and the front faceplate are bonded together at the summit portions of the projecting non-convergence parts using an adhesive, and the width of adhesive layers formed through curing of the adhesive is less than the width of the external light absorbing layers. Consequently, the adverse effects caused by blockage of light are prevented.

What is claimed is:  
     
       1. A lenticular lens sheet that is bonded to a front faceplate and used in a rear projection type screen, the lenticular lens sheet having: 
       a plurality of lenticular lenses arranged on one surface of a light-transmitting substrate; and  
       projecting non-convergence parts arranged on the other surface of the light-transmitting substrate in positions different to positions of convergence of light from said lenticular lenses;  
       wherein an external light absorbing layer that absorbs external light is provided on a summit portion of each of said projecting non-convergence parts,  
       and wherein said lenticular lens sheet and said front faceplate are bonded together at the summit portions of said projecting non-convergence parts using an adhesive, and the width of adhesive layers formed through curing of the adhesive is less than the width of the external light absorbing layers.  
     
     
       2. The lenticular lens sheet according to  claim 1 , wherein the summit portion of each of said projecting non-convergence parts has a convex shape in which a central part thereof is higher than edge parts thereof. 
     
     
       3. The lenticular lens sheet according to  claim 1 , wherein the width of said adhesive layers is more than 70% and less than 90% of the width of said external light absorbing layers, and the thickness of said adhesive layers is no more than 10 μm. 
     
     
       4. The lenticular lens sheet according to  claim 1 , wherein said adhesive is a black adhesive that absorbs external light. 
     
     
       5. The lenticular lens sheet according to  claim 1 , wherein said adhesive is an ultraviolet ray curing type adhesive. 
     
     
       6. The lenticular lens sheet according to  claim 1 , wherein the glass transition temperature of said adhesive after curing is lower than the glass transition temperature of a material used in said front faceplate and said lenticular lens sheet. 
     
     
       7. The lenticular lens sheet according to  claim 1 , wherein the lenticular lens sheet and the front faceplate are curved to project the center of the light-entering side of the front faceplate. 
     
     
       8. A rear projection type screen, comprising the lenticular lens sheet according to claims  1 ,  2 ,  3 ,  4 ,  5 ,  6  or  7 , and a Fresnel lens sheet provided on a light-entering surface side of said lenticular lens sheet. 
     
     
       9. A method of manufacturing a front-faceplate-equipped lenticular lens sheet that is used in a rear projection type screen, has a front faceplate bonded thereto, and has a plurality of lenticular lenses arranged on one surface of a light-transmitting substrate, and projecting non-convergence parts arranged on the other surface of the light-transmitting substrate in positions different to positions of convergence of light from said lenticular lenses, the method comprising the steps of: 
       providing an external light absorbing layer that absorbs external light on a summit portion of each of said projecting non-convergence parts; and  
       bonding said lenticular lens sheet and said front faceplate together using an adhesive at the summit portions of said projecting non-convergence parts, and then curing the adhesive, such that the width of adhesive layers thus formed is less than the width of the external light absorbing layers.  
     
     
       10. The method of manufacturing a lenticular lens sheet according to  claim 9 , wherein the width of said adhesive layers is more than 70% and less than 90% of the width of said external light absorbing layers, and the thickness of said adhesive layers is no more than 10 μm. 
     
     
       11. The method of manufacturing a lenticular lens sheet according to  claim 9 , wherein the step of curing said adhesive comprises a step of half-curing the adhesive before pressing using nip rollers, and a step of curing the adhesive after pressing using the nip rollers. 
     
     
       12. The method of manufacturing a lenticular lens sheet according to  claim 9 , further comprising a step for applying a curvature on the lenticular lens sheet and the front faceplate.